Orchard/src/Orchard.Azure/CloudBlobContainerExtensions.cs

using System;
using System.ComponentModel;
using System.Linq;
using Microsoft.WindowsAzure.StorageClient;

namespace Orchard.Azure {
    public static class CloudBlobContainerExtensions {

        public static bool BlobExists(this CloudBlobContainer container, string path) {
            if ( String.IsNullOrEmpty(path) || path.Trim() == String.Empty )
                throw new ArgumentException("Path can't be empty");

            try {
                using ( new HttpContextWeaver() )
                {
                    var blob = container.GetBlockBlobReference(path);
                    blob.FetchAttributes();
                }
                return true;
            }
            catch ( StorageClientException e ) {
                if ( e.ErrorCode == StorageErrorCode.ResourceNotFound ) {
                    return false;
                }

                throw;
            }
        }

        public static void EnsureBlobExists(this CloudBlobContainer container, string path) {
            if ( !BlobExists(container, path) ) {
                throw new ArgumentException("File " + path + " does not exist");
            }
        }

        public static void EnsureBlobDoesNotExist(this CloudBlobContainer container, string path) {
            if ( BlobExists(container, path) ) {
                throw new ArgumentException("File " + path + " already exists");
            }
        }

        public static bool DirectoryExists(this CloudBlobContainer container, string path) {
            if ( String.IsNullOrEmpty(path) || path.Trim() == String.Empty )
                throw new ArgumentException("Path can't be empty");

            return container.GetDirectoryReference(path).ListBlobs().Count() > 0;
        }

        public static void EnsureDirectoryExists(this CloudBlobContainer container, string path) {
            if ( !DirectoryExists(container, path) ) {
                throw new ArgumentException("Directory " + path + " does not exist");
            }
        }

        public static void EnsureDirectoryDoesNotExist(this CloudBlobContainer container, string path) {
            if ( DirectoryExists(container, path) ) {
                throw new ArgumentException("Directory " + path + " already exists");
            }
        }
    }
}